Multiple tube radiator forced circulation air heating furnace



P 1951 A. B. CARSWELL 2,568,487

MULTIPLE TUBE RADIATOR FORCED CIRCULATION AIR HEATING FURNACE v FiledMay 13, 1948 4 Sheets-Sheet l Inventor ALLAH BRYSON CARSWELL AttorneySept. 18, 1951 4 Sheets-Sheet 2 Filed May 13, 1948 MVN 4 Invehtor ALLAHBRYSON cAnwELL Sept. 18, 1951 A. B. CARSWELL 5 4 MULTIPLE TUBE RADIATORFORCED CIRCULATION AIR HEATING FURNACE Filed May 13, 1948 4 Sheets-Sheet5 Inventor I ALLAH masen cmswELL' Atta rny Septo 1951 A. B. CARSWELL,568,487

MULTIPLE TUBE RADIATOR FORCED CIRCULATION AIR HEATING FURNACE Filed May15, 1948 4 Sheets-Sheet 4 Inventor ALLAH BRYSO CABSWELL v AttorneyPatented Sept. 18, 1951 -u-N rz ?STAT ES FAT OFFICE IMULTIPLE TUBERADIATOR FORCED CIR- CULATION AIR :HEATING FURNACE AllaniBrysonCarswell,otta vafontario; Canada I :Application May 13, 1948,*Seriol` Nermin-89 e6 Claims.

*furnacemand` especially .to one having increased heat transfer areasand amore eflicient routing of the poducts of combustion; from the\ firepot tothe. emergingn smoke pipe.

Among the principal objects ofrtheninvention ara t provide.anovctfurnacastructure that will yieldvup ahighenpercentage of thetotal heatof combuston, enable t the.extraction of substantiarl yuallt the:` heat,fromtheproducts. of combustion reducingthe temperature of ,the output ofnormally-Very: hotfiflua lgases -to, near room .temperatura; andtimwhichztthe essential. parts of the furnace are so arrangedzas to afiTordready, access for cleaning-and seryicing rthattthe i\ unit may be eas lymaintained a in %condition for speak performance e I t A t further.chiesto&thecinvention is to provide a heat-Jtranserring bank ofrfinnedsmoke i tubes removably :mounted inthe furnace to allow of replacementas%single-unit.

It is::further withinthe province of the invention; heroin tdisclosed.to provide ta" hot air, urnace ofa generailysimplified and improveddesign, substantial andrdurabl ;structure and enhancedoperatmgefiiciency andneconomy that is .capable of manufacturen at;relativelytreasonaable i cost.

the accermalish-rnent` of these` and i related objectsasshallbecomezapparent as the: description proceeds, the inventionresidesintheu constmcton, :combination and? arrangement of `partsas-sha-11 :bes hereinafter a more? fully described, illustrated &in {the,accompanyng drawings,` and tpointed-outintheclaims hereunto appended.

3 They invention wi11 bevbest `understoodand can bemcre clearlydescribed whenreference is had tothe-drawings\ forming a :part `:ofthis` disclosure wherein like characters indicate like :parts thrc ghoutthe sewerakviews.

iFigunesr-and 6 are details oftheheat radating finitbeingzana-elevationand section-respectively.

, rwithranelongated rectangular -casing l a fire potrzand-- dome 3 arearrangedxsomewhat-forwardly of a central position. Across the front ofthe dome and in open communication with it is 2 attransversehorizontal`chamher 4. Across .the rearof the furnace, level with the dome: andfront ;chamber `.4, i and spaced somewhat. behind therearof'the `dome is,a smoke outlet manifold chambex. from which the usual smoke-1 11 66emerges. Jtoining the front chamber 4 .and the rear smoke manifold aretwo banksof finned tubes '[oneon either side of the fire pot .dome.3.Just totherearof this dome a vertical transverse bulkhead or, partitionadivides. the furnace cast ing I into fore and aft sections with halftormore of .the i tube banks lying in the forward part. `;..It w i1l=beseen thetopof the casing l is open as` this instant invention is `notconcerned with either thesource or.eventual distribution of the air.However,`theipartition 8 marks .the division betweenther cold air'`in1et 94 and the hot air outlet m. t n

&Below therearsmoke manii'old 5 and the after part ..oi` the tubebanks 1the air,passageww` or route H, passes through filter pads !2 then`enters` oppositecsidesc of a motor driven fan l3ina fannhousing [4inthenlowerurear of the iurnace casingithenceunder the, partition 8 intothe forward section of'the furnace where it encircles the. fire `potand;dome and rises throughthe bankswof i finned smoke tubes 1. tor pass outthrough the cutlet |0`in` the open top of the forward section.

Though myrfurnacetmay be-adapted to any kind of fuelorfiring, Figure 1shows a guntype oil burner |4 inarclosed off compartment the lower'front protected n by -a removable louvered frontuclosurel5. The upper.part" of the .walls and` slopingpart of the top of .the. front sectionof the casing. is insulated asindicated at !6 and maddition.- to :a rdoor !1 `affording access to the fire. pot,. dome .andfnonttransversechamber' 4,' a. hingingbafle. guard I a. is .Suspended.`

Ereferably the.entire furnace is of a all-welded steel construction i.and .the outer ar-rengaging surfaces `of `the dome 3 -and front chamber4 havetradiatingnvanes ,or ribs !9 that serve alsoto strengthen the.deine n structure.

Thebanks of tubes"1 areeach formed asacomplete .and .removable unit. Themultitude. of small, .relatively thin, equally spaced` parallltubes'laarecarried by three panels lb, 'ic and. Td respectively andprovidedwth fireproof, air tight gasketsiare removably Secured tofianges 20 at thei front compartment, the partition 8 and the innern.walleofjthe reansmoke manifoldj.` On the' back ofthe casing"|,` in linewith each' bank of tubes 'I is a clean out door 2l of sufiicient size toallow for the installation and removal of a complete bank. spacedlongitudinally along the banks of tubes are thin, vertical, transverselyextending sheet metal radiating fins 'le having perforations 'If to passthe fins, and the perforations fianged as at Tg. The fin perforationshave a tight, frictional engagement with the tubes so the expanding ofthe metal on heating increases the conductivity of the connection. Likeall other joints in this furnace, the tubes are welded to the panels,especially 'lb and 1d, although the partition engaging panel 'Ic may bean enlarged fin.

The cross sectional area of the tubes Ta is such as to offer noobstruction to the flow of the products of combustion therethrough evenwith the greater surface frictional engagement encountered and beingsmall and finned and of considerable length the gases fiowingtherethrough are able to give up almost completely of their heat unitsbefore emerging into the rear smoke manifold 5. The down draft ofincoming cold air entering 'through the open top 9 of the rear sectionpasses over the rear ends of the already partly cooled banks of tubesTa, and is partially warmed while taking up most of the remaining heatof the fiue gases in the tube banks. Thus the current ofair is raised toa higher temperature than would otherwise be the case by contact withthe ribbed fire box dome and the very hot front sections of the tubebanks before leaving the front section furnace outlet o.

From the foregoing description taken in connection with the accompanyingdrawings, it will be manifest that an efficient and economicalfurnaceisprovided that will fulfill all the necessary requirements ofsuch a device, but as many changes could be made in the abovedescription andpmanv apparently widely different embodiments of theinvention may be constructed within the scope of the appended claims,without departing from the spirit or scope thereof, it is intended thatall matters contained in the said acompanying specification and drawingsshall be interpreted as illustrative and not in a limitative orrestrictive sense;

. Having thus described the invention, what I claim as new and desire tosecure by Letters Paten s: i, 1 A furnace comprising a fire pot fueledfrom the front and dome surmounting the same, a transversely disposedchamber forward of said dome in communication therewith, a transverselydisposed outlet manifold to the rear of said dome, removable banks ofhorizontal tubes on each side of said dome connecting said chamber andmanifold and a, casing therefor with an inlet at the upper rear portionand an outlet at the upper front portion thereof and having an airpassageway therethrough beginning over the rear of said banks of tubesand subsequently crossing the forward ends of said banks of tubes.

2. A furnace comprising an outer casing, a front fueled fire pot andsurmounting dome therein forwardly of centre, a transversely disposedchamber in front of said dome centrally open thereto, a transverselydisposed outlet manifold in the rear of said casing and spaced adistance back of said dome, a unitary removable bank of heat transfertubes on each side of said dome connecting said chamber and saidmanifold, a vertical transverse partition in said casing extendingacross said casing from side to side and downwardly from the top to apoint spaced above the bottom thereof and disposed to the rear of saiddome and a fan circulating air down the back of said partition and upthe front; said casing having air inlet and outlet openings disposedrespectively to the rear and front of said partiton and both locatedabove the lower edge thereof.

3. The combination with the structure set forth in claim 2, of a cleanout door in the back of said casing in line with each of said banks oftubes and wherein said banks of tubes are each removable long itudinallythrough said doors as a in claim 2, wherein a heat transferring bank oftubes consists of a plurality of elongated horizontal tubes, radiatingfins spaced therealong, formed of sheet metal and perforated to pass themany tubes of the bank, the perforations being of a size and flanged tohave tight fltting engagement with the tubes.

6. An all-welded steel furnace comprising an outer shell or casing opento the top, a vertical. transverse partition dividing said casinglongitudinally into front and rear sections with an opening through thebottom thereof, an air circulating fan directed forwardly through saidpartition opening so a current of air is drawn into the casing throughthe open top of the rear section, passed under said partition andexpelled through the open top of the front section, a fire pot and domein said casing forwardly of said partition, a transversely disposedchamber across the front of and in communication with said dome beingopen thereto throughout its height for the full width of said dome, atransversely disposed outlet manifold in the rear of said casing andspaced a distance back of said partition and a bank of finned heattransfer tubes on each side of said dome connecting said front chamberand said rear manifold, said banks being longitudinally removablethrough the back of said casing and sealed where 'they fasten to saidchamber and manifold with fireproof air-tight gaskets.

ALLAN BRYSON CARSWELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

